Description

Experiencing significantly degraded response quality on Claude Opus 4.6 via Claude Code over the past few hours (April 3, 2026). Responses feel slow, unfocused, and lower quality than usual — "brain fog" is the best description.

Context

• This follows known incidents from March 31 – April 1 (Opus 4.6 / Sonnet 4.6 timeouts, Haiku 4.5 elevated errors)
• Status page shows all clear as of April 2, but the degraded quality persists
• Fresh conversations don't resolve it
• Model: Claude Opus 4.6 via Claude Code CLI

Expected behavior

Normal response quality and coherence.

Actual behavior

Noticeably worse reasoning, coherence, and overall response quality compared to baseline.

Environment

• Claude Code CLI (latest)
• macOS (Darwin 24.1.0)
• Model: claude-opus-4-6